The aim of this study is to investigate the pathophysiologic mechanisms involved in bacteria-induced choroiditis with serous retinal detachment in dogs by documenting the natural history and the histopathologic correlation of the fundus lesions, by observing the effect of certain drugs on the course of the fundus lesions, and by determining if only certain bacteria produce fundus lesions. Furthermore, it is proposed to determine if dead bacteria produce fundus lesions and whether fundus lesions, similar to the ones seen in dogs, develop in monkeys. Indirect ophthalmoscopy will be used to examine the fundus after intracarotid injection of bacteria. Fundus photography and histopathologic examination will document the clinical and pathologic findings of the fundus lesions.